in Japan, if you are on death row, you have no idea when you will die. They keep the date secret as a way to fuck with the inmates. One day you are in your cell and suddenly guards appear and say "its time. You are gonna die in 10 minutes"
And that's it
I think they just march you out to a yard with a noose, or they do a firing squad. I think those are the 2 methods used. Not sure if Japan does lethal injection